diff --git a/flask_api_security/requirements.txt b/flask_api_security/requirements.txt
index 1a4888e..7b4e6d8 100644
--- a/flask_api_security/requirements.txt
+++ b/flask_api_security/requirements.txt
@@ -2,15 +2,15 @@ blinker==1.4
 certifi==2018.1.18
 chardet==3.0.4
 click==6.7
-Flask==0.12.2
+flask==0.12.2
 future==0.16.0
 idna==2.6
 itsdangerous==0.24
-Jinja2==2.10
-MarkupSafe==1.0
+jinja2==2.10
+markupsafe==1.0
 pycryptodomex==3.5.1
 pyjwkest==1.4.0
 requests==2.18.4
 six==1.11.0
 urllib3==1.22
-Werkzeug==0.14.1
+werkzeug==0.15.3